TandemGeek

Given the shifting issues are at the front derailleur, all of the photos may not be essential. However, before taking my best guess at a possible cause and solution for your shifting woes I will note that just looking at the photos you've posted in the past, it does appear you have a little more cable housing between the bars and downtube and also at the rear derailleur than you probably need.

Anyway, since you've mentioned that the shifting was also sub-optimal on your Robusta I'm going to go out on a limb here and offer up some comments regarding tandems, front derailleurs and shifting technique that may allow you to get some better shifting performance out of your current set-up. Just based on the specs, if the Record Triple FD is what I think it is, that shouldn't be a problem as we're using nearly the same thing on our current tandem with the same Record Ergo shifters, daVinci cranks, FSA chain rings (albeit with different sized rings) and an even more narrow chain line. With regard to the chain rings, I'm not quite sure why FSA decided that 53/39/30 was the sweet spot for tandems, other than giving the middle chain ring a little more umphf for climbs without resorting to the smallest chain ring. In any event, I ran 54/44/32 on our tandems from '98 - '07 with a few other combinations thrown in that didn't work as well, e.g., 54/42/28, 54/44/30 and we're currently running 53/42/30 which works quite well. I've ridden a tandem with the 53/39/30 FSAs and just didn't like the big jump that I had also experienced with our initial 54/42/28 set-up back in '98. Anyway, less I digress.... the bottom line is everything you have should work just fine. The only thing I use that's different is with regard to chains since I've always used Shimano cassettes instead of Campy on our tandems. That would have been a discriminator if you were having rear shifting issues, but it's a moot point given it's the front derailleur / shifting that's giving you fits.

OK, Q&A time

A. Does the shifting become finicky all the time (aka, just riding along) or is it in specific circumstances such as when climbing under heavy pedal loads? Appears on flats, rolling and climbing. Both the shop (I trust my mechanic implicitly) and I have adjusted things. Generally it will work fine for a ride or two, then it quickly goes down hill.

This seems to suggest technique may be playing a greater role vs. 100% set-up as there just isn't that much that can go out of adjustment WRT the front derailleur. I say this as most of us tend to be very attentive to things right after making adjustments such as shifting technique, but then fall back into our normal habits only to find that problems have returned.


B. Is it the front derailleur performance that's sluggish and, if so, between which shifts. It is the front. Sometimes it won't drop from the middle to the small. Sometimes won't go from the middle to the large. And then sometimes I am trying to go large to middle and find myself in the small with no issue at all. Also, sometimes the behavior is dependent on the gear I am in, sometimes not.

Again, balky shifting at the front derailleur / drive rings can be indicative of attempting to shift while the drive train is still heavily loaded with either you and/or your stoker applying nearly full power to the pedals.

Many tandem teams will experience this on climbs when they attempt to downshift from the middle to the small chain ring AFTER they have allowed their cadence to fall and are grinding out a gear that is too tall for the grade. In this situation, the amount of torque being exerted by the chain on the drive rings exceeds the power of the spring in the front derailleur as it attempts to push the chain off the middle ring to the smaller ring, hence there's a lot of noise but no gear change. However, in some other instances a team will let up just enough to allow the chain to derail while it is still under a very high load where that load will simply be too high to allow the chain to engage the small chain ring's teeth causing it to simply skip and slip past the small ring and fall to the bottom bracket where bad things can happen.

Having the drive train loaded-up can also create the same or similar problems with all downshifts as well as upshifts, even on drive rings that have ramps and pins. Again, given a front derailleur works by pure brute force (even more so than the rear), tandems inherently require more finesse and better technique to overcome the much higher chain loads generated by two (or more) riders pushing a gear with 1.5x to 2x or more torque than the captain deals with on their single bike. Therefore, if you don't over compensate by learning to incorporate a very slight soft pedal stroke that accompanies your shifts, front shifting will typically remain balky on a tandem. In most cases, the captain can do this without bothering the stoker because it's the sum of both rider's power that creates the problem. However, if you're blessed with a super-stoker who can really turn out the watts, they may need to be coached to 'lighten up' when shifting from the middle to the small chain rings specifically on climbs and perhaps in other riding situations.


C. Is it the rear shifting that goes off and, if so, is it specific to any chainring combination? As far as the rear goes, other than dealing with the initial cable stretch, all seems pretty good back there. Occasional hiccup when it doesn't quite hit things dead on, but generally rights itself after a shift or two.

Having used Campy Ergo on our tandems since '98 I've found that there will always be times when a little 'English' needs to be applied to the upshift lever to nudge the derailleur when there's a bit of chatter coming from the rear cluster or, as you note, a full upshift / downshift to get things back in alignment. I suspect it's simply cable drag/stretch and, well, other than having very clean / short cable housings, inserting teflon sleeves in the cable guides and putting new cables on each year there's not a whole lot you can do other than learning how to compensate on the fly.


D. How fast does it degrade: 20 miles, 100 miles, 1000 miles? 40 to 75 miles. That's a guess. I am generally thinking in terms of the number if rides.

I think I covered this one already.


E. Other details???? We also tried moving the spindle (steel Phil Wood, 118 length) for the BB slightly off center (to the drive side) to see if that would do anything since centered wasn't working well. That hasn't helped either.

You can certainly do some fine tuning with chain line adjustments, but in general it only really helps to eliminate chain chatter in certain really bad cross-over situations which, well, most of us try to avoid. FWIW, I've used 108mm, 111mm and 113mm rear spindles on three different 145mm rear-spaced tandems and they all have worked fine. We're currently running a 111mm with perhaps a little bit of off-set and I suspect we have the same FSA chain rings on our Calfee's daVinci cranks that you're using on your Macchiatto's daVinci cranks. So, again, I'd be more inclined to look towards technique.